I'm unaware of such a tool. I can't imagine something like that being up to date and accurate. Produce retail is market driven and it can change daily. If prices are you primary motivator the Asian shops in the Richmond are the way to go. I think #2 Clement is at @ 6th Ave. on Clement. Just walk the street. There are several options.

I avoid Whole Foods because I resent its offering so many commercial products under the aura of a health food store logo/name. However, its produce is pretty good and v. price-y.

For Latin-American produce at excellent prices, 24th Street more or less between Potrero & Mission.

Stockton Street in Chinatown is a trip! As pointed out, Chinese markets also plentiful on Clement. However, the Sunset is another option, since there are so many reasonably priced and good Chinese restaurants in that area, I'd bet there are also some good produce markets along Irving, Noriega, Taraval,the major shopping streets. There's a very popular one at Irving/22nd Ave.

Your mention of Tantillo triggered a nostalgic memory of Joe Carcione ("The Greengrocer"), who was really in the forefront of the fresh produce movement locally. I can still hear his raspy, Italian-accented voice rhapsodising over his latest finds.